Joseph Wright writes:
> Morten Høgholm wrote:
>
> [snip]
> > From l3messages:
> >
> > % \begin{macro}{\text_put_sp:}
> > % \begin{macro}{\text_put_four_sp:}
> > %    We need these functions for certain error and warning messages
> > %    right away. They put one and four spaces into the message stream.
> > %    \begin{macrocode}
> > \def_new:Npn \text_put_sp: {~}
> > \def_new:Npn \text_put_four_sp: {\text_put_sp: \text_put_sp:
> >                                  \text_put_sp: \text_put_sp: }
> > %    \end{macrocode}
> > % \end{macro}
> > % \end{macro}
> > %
>
> As you may have guessed, I'm using source quite heavily for finding
> things I suspect may exist.  \text_put_sp: is not in the "documentation"
> part of source3, so doesn't show up by default.  Looking at l3messages,
> it seems there is quite a bit that doesn't make it to the "use" part.  I
> shall read the implementation properly on this.

some of it is probably simply neglect, some of it is because some stuff is
more experimental or not fully thought through ...

frank